Key takeaways

  • Mean weight reduction of approximately −8.0% over 56 weeks at the 3.0mg dose (SCALE trial).
  • Daily subcutaneous injection — practical drawback compared to weekly newer options.
  • Approved 2010 for diabetes (Victoza), 2014 for obesity (Saxenda) — the longest-standing GLP-1 in clinical use.
  • Modest effect size relative to semaglutide and tirzepatide; primarily relevant when those are unavailable.
  • UK: POM. Saxenda available via NHS for narrow eligibility and via private clinics.

What it is

Liraglutide is a 31-amino-acid GLP-1 receptor agonist with 97% homology to native human GLP-1. A C16 fatty acid (palmitic acid) attached to the peptide backbone enables albumin binding and resistance to DPP-4 cleavage, extending the half-life to ~13 hours and supporting once-daily subcutaneous dosing.

It was approved for type-2 diabetes (Victoza, 2010) and chronic weight management (Saxenda, 2014), making it the longest-marketed GLP-1 receptor agonist. In most modern contexts it has been superseded by semaglutide and tirzepatide on efficacy, but its dosing schedule and tolerability profile still suit some users.

How it works

Mechanism is identical in principle to semaglutide — single-receptor GLP-1 agonism. The shorter half-life means less stable plasma levels and a more frequent dosing burden, but a faster off-time when needed.

Step 1
Daily injection

Subcutaneous dose binds to albumin, persists ~13 hours.

Step 2
GLP-1 receptor binding

Activates pancreatic, gut, and CNS receptors.

Step 3
Insulin & glucagon control

Glucose-dependent insulin release; glucagon suppression.

Step 4
Satiety signalling

Slowed gastric emptying; central appetite reduction.

Benefits

Weight reduction (high confidence)

The SCALE trial program (n=3,731 across studies) reported mean weight reduction of approximately −8.0% over 56 weeks at the 3.0mg dose vs −2.6% on placebo. Clinically meaningful, but smaller than semaglutide (−14.9%) or tirzepatide (−20.9%) at their respective maximum doses.

Cardiovascular outcomes (high confidence)

The LEADER trial (n=9,340, type-2 diabetes population) reported a 13% relative reduction in MACE over 3.8 years of follow-up. Liraglutide was the first GLP-1 to demonstrate cardiovascular benefit in a CVOT.

Compared to newer options
Both efficacy and dosing convenience favour semaglutide or tirzepatide for most modern weight-management contexts. Liraglutide remains a reasonable option where weekly injections are unavailable, where shorter wash-out is preferred, or where cost considerations favour it on the NHS.

Research summary

A randomised, controlled trial of liraglutide for weight management (SCALE Obesity)
2015
Phase-3 RCT, double-blind·n = 3,731

−8.0% mean weight reduction at 56 weeks on 3.0mg vs −2.6% on placebo. 63.2% achieved ≥5% reduction; 33.1% achieved ≥10%.

N Engl J Med · doi:10.1056/NEJMoa1411892
Liraglutide and cardiovascular outcomes in type-2 diabetes (LEADER)
2016
Phase-3 RCT, primary CV outcomes·n = 9,340

13% relative reduction in MACE composite (HR 0.87, 95% CI 0.78–0.97). First demonstration of CV benefit for any GLP-1 agonist.

N Engl J Med · doi:10.1056/NEJMoa1603827
Semaglutide vs liraglutide for weight loss (STEP-8)
2022
Phase-3 RCT, head-to-head·n = 338

Semaglutide 2.4mg produced significantly greater weight reduction than liraglutide 3.0mg over 68 weeks (−15.8% vs −6.4%).

JAMA · doi:10.1001/jama.2021.23619

Dosage & administration

Liraglutide for weight management requires daily subcutaneous injection, with a 4-week titration schedule.

PhaseDoseDurationNotes
Week 10.6 mg / day7 daysTitration only
Week 21.2 mg / day7 daysTitration
Week 31.8 mg / day7 daysTitration
Week 42.4 mg / day7 daysTitration
Maintenance3.0 mg / day—Approved obesity dose
Saxenda titration per UK SmPC. Victoza (diabetes) maxes at 1.8mg.

Side effects & safety

Profile broadly resembles other GLP-1 agonists. GI symptoms dominate; tolerance improves over time.

EffectFrequencySeverity
Nausea39%Mild–moderate
Diarrhoea21%Mild
Constipation19%Mild
Vomiting16%Mild–moderate
Hypoglycaemia (in T2D)~10%Mild–moderate
Acute pancreatitis<0.5%Serious — discontinue

Contraindications: Personal/family history of medullary thyroid carcinoma or MEN-2. Active pancreatitis. Pregnancy.

Prescription-only medicine (POM) in the UK
Saxenda (3.0mg, obesity) and Victoza (1.8mg, diabetes) are licensed POMs. NHS access for Saxenda is restricted under NICE TA664 to specific BMI thresholds and clinical contexts. Available privately through regulated UK clinics; counterfeit pens are documented but less common than for newer GLP-1 agonists.

Summary

Liraglutide is a well-evidenced first-generation GLP-1 with a meaningful effect on weight and cardiovascular endpoints. In most modern contexts, semaglutide or tirzepatide will be preferred — both for larger effect sizes and weekly dosing. Liraglutide remains relevant where those are not accessible, where its shorter half-life is clinically preferable, or where cost dominates the decision. UK availability is straightforward through both NHS and private routes.

References (5)
  1. Pi-Sunyer X, et al. A randomised, controlled trial of 3.0 mg of liraglutide in weight management (SCALE). N Engl J Med. 2015;373(1):11-22.
  2. Marso SP, et al. Liraglutide and cardiovascular outcomes in type 2 diabetes (LEADER). N Engl J Med. 2016;375(4):311-322.
  3. Rubino DM, et al. Semaglutide 2.4mg once weekly vs liraglutide 3.0mg once daily (STEP-8). JAMA. 2022;327(2):138-150.
  4. NICE TA664. Liraglutide for managing overweight and obesity. December 2020.
  5. MHRA. Saxenda 6mg/mL solution for injection — Summary of Product Characteristics.
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